Gamma-ray Burst 190718A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 18 Jul 19 04:41:35 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     915091,   Seg_Num: 0
GRB_RA:          336.531d {+22h 26m 07s} (J2000),
                 336.819d {+22h 27m 17s} (current),
                 335.791d {+22h 23m 10s} (1950)
GRB_DEC:         -41.221d {-41d 13' 13"} (J2000),
                 -41.121d {-41d 07' 13"} (current),
                 -41.475d {-41d 28' 30"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       1121 [cnts]    Image_Peak=80 [image_cnts]
TRIGGER_DUR:     0.512 [sec] 
TRIGGER_INDEX:   127     E_range: 50-350 keV
BKG_INTEN:       10050 [cnts]
BKG_TIME:        16864.74 SOD {04:41:04.74} UT
BKG_DUR:         8 [sec]
GRB_DATE:        18682 TJD;   199 DOY;   19/07/18
GRB_TIME:        16875.17 SOD {04:41:15.17} UT
GRB_PHI:          25.78 [deg]
GRB_THETA:        10.19 [deg]
SOLN_STATUS:     0x83
RATE_SIGNIF:     18.13 [sigma]
IMAGE_SIGNIF:    6.69 [sigma]
MERIT_PARAMS:     +1  +0  +0  -1  +3  -4  +0  +0 +78  +0 
SUN_POSTN:       117.26d {+07h 49m 03s}  +21.07d {+21d 04' 23"}
SUN_DIST:        141.12 [deg]   Sun_angle= 9.4 [hr] (West of Sun)
MOON_POSTN:      312.72d {+20h 50m 53s}  -19.82d {-19d 48' 54"}
MOON_DIST:        29.56 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      358.09,-57.12 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      322.11,-29.04 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This is a rate trigger.  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        Since the IMAGE_SIGNIF is less than 7 sigma, this is a questionable detection.  
COMMENTS:        This trigger occurred at longitude,latitude = 350.16,12.03 [deg].

red DSS finding chart ps-file

GCN NOTICE

 
TITLE:           GCN/SWIFT NOTICE 
NOTICE_DATE:     Thu 18 Jul 19 04:42:29 UT 
NOTICE_TYPE:     Swift-XRT Nack-Position 
TRIGGER_NUM:     915091,   Seg_Num: 0 
POINT_RA:        336.531d {+22h 26m 07s} (J2000) 
POINT_DEC:       -41.215d {-41d 12' 55"} (J2000) 
IMG_START_DATE:  18682 TJD;   199 DOY;   19/07/18 
IMG_START_TIME:  16941.58 SOD {04:42:21.58} UT,   66.4 [sec] since BAT Trigger Time
COUNTS:          3    Min_needed= 20 
STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec] 
PH2_ITER:        1    Max_iter_allowed= 4 
ERROR_CODE:      1 
COMMENTS:        SWIFT-XRT Nack Position.   
COMMENTS:        No source found in the image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 18 Jul 19 04:45:15 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     915091,   Seg_Num: 0
POINT_RA:        336.531d {+22h 26m 07s} (J2000)
POINT_DEC:       -41.215d {-41d 12' 54"} (J2000)
POINT_ROLL:      109.222d
IMG_START_DATE:  18682 TJD;   199 DOY;   19/07/18
IMG_START_TIME:  16944.85 SOD {04:42:24.85} UT,   69.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.861
N_STARS:         27
X_OFFSET:        506 [pixels]
Y_OFFSET:        593 [pixels]
X_MAX:           1465 [pixels]
Y_MAX:           1552 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    6
SL_URL:          sw00915091000msufc0069.fits
SUN_POSTN:       117.27d {+07h 49m 04s}  +21.07d {+21d 04' 21"}
SUN_DIST:        141.12 [deg]   Sun_angle= 9.4 [hr] (West of Sun)
MOON_POSTN:      312.75d {+20h 51m 00s}  -19.81d {-19d 48' 33"}
MOON_DIST:        29.54 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      358.10,-57.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      322.11,-29.04 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 18 Jul 19 04:45:28 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     915091,   Seg_Num: 0
POINT_RA:        336.531d {+22h 26m 07s} (J2000)
POINT_DEC:       -41.215d {-41d 12' 54"} (J2000)
POINT_ROLL:      109.222d
IMG_START_DATE:  18682 TJD;   199 DOY;   19/07/18
IMG_START_TIME:  16944.85 SOD {04:42:24.85} UT,   69.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.861
N_STARS:         27
X_OFFSET:        506 [pixels]
Y_OFFSET:        593 [pixels]
X_MAX:           1465 [pixels]
Y_MAX:           1552 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    6
SL_URL:          sw00915091000msufc0069.fits
SUN_POSTN:       117.27d {+07h 49m 04s}  +21.07d {+21d 04' 21"}
SUN_DIST:        141.12 [deg]   Sun_angle= 9.4 [hr] (West of Sun)
MOON_POSTN:      312.75d {+20h 51m 01s}  -19.81d {-19d 48' 32"}
MOON_DIST:        29.54 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      358.10,-57.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      322.11,-29.04 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 18 Jul 19 04:46:42 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     915091,   Seg_Num: 0
POINT_RA:        336.531d {+22h 26m 07s} (J2000)
POINT_DEC:       -41.215d {-41d 12' 54"} (J2000)
ROLL:            109.222d
IMG_START_DATE:  18682 TJD;   199 DOY;   19/07/18
IMG_START_TIME:  16944.85 SOD {04:42:24.85} UT,   69.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     585117768
X_OFFSET:        825 [pixels]
Y_OFFSET:        912 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       985
Y_GRB_POS:       1072
BINNING_INDEX:   1
IM_URL:          sw00915091000msuni0093.fits
SUN_POSTN:       117.27d {+07h 49m 04s}  +21.07d {+21d 04' 21"}
SUN_DIST:        141.12 [deg]   Sun_angle= 9.4 [hr] (West of Sun)
MOON_POSTN:      312.76d {+20h 51m 03s}  -19.81d {-19d 48' 25"}
MOON_DIST:        29.53 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      358.10,-57.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      322.11,-29.04 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 18 Jul 19 04:46:43 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     915091,   Seg_Num: 0
GRB_RA:          336.531d {+22h 26m 07s} (J2000),
                 336.819d {+22h 27m 17s} (current),
                 335.791d {+22h 23m 10s} (1950)
GRB_DEC:         -41.221d {-41d 13' 13"} (J2000),
                 -41.121d {-41d 07' 13"} (current),
                 -41.475d {-41d 28' 30"} (1950)
GRB_DATE:        18682 TJD;   199 DOY;   19/07/18
GRB_TIME:        16875.17 SOD {04:41:15.17} UT
TRIGGER_INDEX:   127
GRB_PHI:          25.78 [deg]
GRB_THETA:        10.19 [deg]
DELTA_TIME:      77.00 [sec]
TRIGGER_DUR:     0.512 [sec] 
SOLN_STATUS:     0x83
RATE_SIGNIF:     18.13 [sigma]
IMAGE_SIGNIF:    6.69 [sigma]
LC_URL:          sw00915091000msb.lc
SUN_POSTN:       117.27d {+07h 49m 04s}  +21.07d {+21d 04' 21"}
SUN_DIST:        141.12 [deg]   Sun_angle= 9.4 [hr] (West of Sun)
MOON_POSTN:      312.76d {+20h 51m 03s}  -19.81d {-19d 48' 25"}
MOON_DIST:        29.54 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      358.09,-57.12 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      322.11,-29.04 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Lightcurve.  
COMMENTS:           
COMMENTS:        The next comments were copied from the BAT_POS Notice:  
COMMENTS:        This is a rate trigger.  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        Since the IMAGE_SIGNIF is less than 7 sigma, this is a questionable detection.  
COMMENTS:        This trigger occurred at longitude,latitude = 350.16,12.03 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 18 Jul 19 04:46:56 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     915091,   Seg_Num: 0
POINT_RA:        336.531d {+22h 26m 07s} (J2000)
POINT_DEC:       -41.215d {-41d 12' 54"} (J2000)
ROLL:            109.222d
IMG_START_DATE:  18682 TJD;   199 DOY;   19/07/18
IMG_START_TIME:  16944.85 SOD {04:42:24.85} UT,   69.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     585117768
X_OFFSET:        825 [pixels]
Y_OFFSET:        912 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       985
Y_GRB_POS:       1072
BINNING_INDEX:   1
IM_URL:          sw00915091000msuni0093.fits
SUN_POSTN:       117.27d {+07h 49m 04s}  +21.07d {+21d 04' 21"}
SUN_DIST:        141.12 [deg]   Sun_angle= 9.4 [hr] (West of Sun)
MOON_POSTN:      312.77d {+20h 51m 04s}  -19.81d {-19d 48' 23"}
MOON_DIST:        29.53 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      358.10,-57.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      322.11,-29.04 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 18 Jul 19 04:46:20 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     915091,   Seg_Num: 0
GRB_RA:          336.5760d {+22h 26m 18.24s} (J2000),
                 336.8640d {+22h 27m 27.35s} (current),
                 335.8367d {+22h 23m 20.80s} (1950)
GRB_DEC:         -41.2027d {-41d 12' 09.7"} (J2000),
                 -41.1028d {-41d 06' 09.9"} (current),
                 -41.4574d {-41d 27' 26.7"} (1950)
GRB_ERROR:       3.7 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  18682 TJD;   199 DOY;   19/07/18
IMG_START_TIME:  16957.00 SOD {04:42:37.00} UT,   81.8 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       117.27d {+07h 49m 04s}  +21.07d {+21d 04' 21"}
SUN_DIST:        141.09 [deg]   Sun_angle= 9.4 [hr] (West of Sun)
MOON_POSTN:      312.76d {+20h 51m 03s}  -19.81d {-19d 48' 27"}
MOON_DIST:        29.55 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      358.11,-57.16 [deg] galactic lon,lat of the burst
ECL_COORDS:      322.15,-29.04 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        TAM values, flux and significance fields are not valid.  
COMMENTS:        This position was automatically generated on the ground using  
COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).  
COMMENTS:        See http://www.swift.ac.uk/sper/docs.php for details.  
COMMENTS:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 0.58% < P(seren) < 1.1%.

GCN Circular #25082
V. D'Elia (SSDC), E. Ambrosi (INAF-IASFPA), A. D'Ai (INAF-IASFPA), N. J. Klingler (PSU), D. M. Palmer (LANL) and A. Tohuvavohu (PSU) report on behalf of the Neil Gehrels Swift Observatory Team:
At 04:41:15 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 190718A (trigger=915091). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 336.531, -41.221 which is
```
   RA(J2000) = 22h 26m 07s
   Dec(J2000) = -41d 13' 13"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure with a duration of about 20 sec. The peak count rate was ~1700 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 04:42:21.5 UT, 66.4 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 336.57614, -41.20264 which is equivalent to:
```
   RA(J2000)  = 22h 26m 18.27s
   Dec(J2000) = -41d 12' 09.5"
```
with an uncertainty of 3.6 arcseconds (radius, 90% containment). This location is 138 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper.
A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (1.24 x 10^20 cm^-2, Willingale et al. 2013), with an excess column of 4.3 (+2.81/-2.43) x 10^21 cm^-2 (90% confidence).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 69 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers none of the XRT error circle. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.01.
Burst Advocate for this burst is V. D'Elia (delia AT ssdc.asi.it). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/)

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 18 Jul 19 05:09:20 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     915091,   Seg_Num: 0
POINT_RA:        336.532d {+22h 26m 08s} (J2000)
POINT_DEC:       -41.214d {-41d 12' 49"} (J2000)
POINT_ROLL:      109.219d
IMG_START_DATE:  18682 TJD;   199 DOY;   19/07/18
IMG_START_TIME:  17157.09 SOD {04:45:57.09} UT,   281.9 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.534
N_STARS:         39
X_OFFSET:        266 [pixels]
Y_OFFSET:        353 [pixels]
X_MAX:           1705 [pixels]
Y_MAX:           1792 [pixels]
DET_THRESH:      7
PHOTO_THRESH:    3
SL_URL:          sw00915091000msufc0281.fits
SUN_POSTN:       117.28d {+07h 49m 08s}  +21.07d {+21d 04' 11"}
SUN_DIST:        141.13 [deg]   Sun_angle= 9.4 [hr] (West of Sun)
MOON_POSTN:      312.96d {+20h 51m 51s}  -19.77d {-19d 46' 15"}
MOON_DIST:        29.44 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      358.10,-57.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      322.11,-29.03 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 18 Jul 19 05:09:39 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     915091,   Seg_Num: 0
POINT_RA:        336.532d {+22h 26m 08s} (J2000)
POINT_DEC:       -41.214d {-41d 12' 49"} (J2000)
POINT_ROLL:      109.219d
IMG_START_DATE:  18682 TJD;   199 DOY;   19/07/18
IMG_START_TIME:  17157.09 SOD {04:45:57.09} UT,   281.9 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.534
N_STARS:         39
X_OFFSET:        266 [pixels]
Y_OFFSET:        353 [pixels]
X_MAX:           1705 [pixels]
Y_MAX:           1792 [pixels]
DET_THRESH:      7
PHOTO_THRESH:    3
SL_URL:          sw00915091000msufc0281.fits
SUN_POSTN:       117.28d {+07h 49m 08s}  +21.07d {+21d 04' 11"}
SUN_DIST:        141.13 [deg]   Sun_angle= 9.4 [hr] (West of Sun)
MOON_POSTN:      312.97d {+20h 51m 52s}  -19.77d {-19d 46' 14"}
MOON_DIST:        29.44 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      358.10,-57.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      322.11,-29.03 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 18 Jul 19 05:10:26 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     915091,   Seg_Num: 0
POINT_RA:        336.532d {+22h 26m 08s} (J2000)
POINT_DEC:       -41.214d {-41d 12' 49"} (J2000)
ROLL:            109.219d
IMG_START_DATE:  18682 TJD;   199 DOY;   19/07/18
IMG_START_TIME:  17157.09 SOD {04:45:57.09} UT,   281.9 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     585117980
X_OFFSET:        825 [pixels]
Y_OFFSET:        912 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       985
Y_GRB_POS:       1072
BINNING_INDEX:   1
IM_URL:          sw00915091000msuni0305.fits
SUN_POSTN:       117.28d {+07h 49m 08s}  +21.07d {+21d 04' 11"}
SUN_DIST:        141.13 [deg]   Sun_angle= 9.4 [hr] (West of Sun)
MOON_POSTN:      312.97d {+20h 51m 53s}  -19.77d {-19d 46' 09"}
MOON_DIST:        29.44 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      358.10,-57.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      322.11,-29.03 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 18 Jul 19 05:10:38 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     915091,   Seg_Num: 0
POINT_RA:        336.532d {+22h 26m 08s} (J2000)
POINT_DEC:       -41.214d {-41d 12' 49"} (J2000)
ROLL:            109.219d
IMG_START_DATE:  18682 TJD;   199 DOY;   19/07/18
IMG_START_TIME:  17157.09 SOD {04:45:57.09} UT,   281.9 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     585117980
X_OFFSET:        825 [pixels]
Y_OFFSET:        912 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       985
Y_GRB_POS:       1072
BINNING_INDEX:   1
IM_URL:          sw00915091000msuni0305.fits
SUN_POSTN:       117.28d {+07h 49m 08s}  +21.07d {+21d 04' 10"}
SUN_DIST:        141.13 [deg]   Sun_angle= 9.4 [hr] (West of Sun)
MOON_POSTN:      312.97d {+20h 51m 54s}  -19.77d {-19d 46' 08"}
MOON_DIST:        29.44 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      358.10,-57.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      322.11,-29.03 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 18 Jul 19 05:09:56 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     915091,   Seg_Num: 0
GRB_RA:          336.5761d {+22h 26m 18.26s} (J2000),
                 336.8641d {+22h 27m 27.37s} (current),
                 335.8368d {+22h 23m 20.83s} (1950)
GRB_DEC:         -41.2040d {-41d 12' 14.4"} (J2000),
                 -41.1041d {-41d 06' 14.6"} (current),
                 -41.4587d {-41d 27' 31.4"} (1950)
GRB_ERROR:       2.1 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  18682 TJD;   199 DOY;   19/07/18
IMG_START_TIME:  16957.00 SOD {04:42:37.00} UT,   81.8 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       117.28d {+07h 49m 08s}  +21.07d {+21d 04' 11"}
SUN_DIST:        141.10 [deg]   Sun_angle= 9.4 [hr] (West of Sun)
MOON_POSTN:      312.97d {+20h 51m 52s}  -19.77d {-19d 46' 12"}
MOON_DIST:        29.46 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      358.11,-57.15 [deg] galactic lon,lat of the burst
ECL_COORDS:      322.15,-29.04 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        This is an Update Notice -- the RA,Dec values herein supersede the previous XRT_POS Notice.  
COMMENTS:        TAM values, flux and significance fields are not valid.  
COMMENTS:        This position was automatically generated on the ground using  
COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).  
COMMENTS:        See http://www.swift.ac.uk/sper/docs.php for details.  
COMMENTS:        This position was enhanced using UVOT field astrometry.  
COMMENTS:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 0.58% < P(seren) < 1.1%.

GCN Circular #25082
V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva, D.Kuvshinov (Lomonosov Moscow State University, SAI, Physics Department),
R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA),
H.Levato (Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),
R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias)
D. Buckley (South African Astronomical Observatory),
O.A. Gres, N.M. Budnev, O.Ershova (Irkutsk State University, API),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
V. Yurkov, A. Gabovich, Yu. Sergienko (Blagoveschensk Educational State University)
MASTER-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) was pointed to the Swift GRB190718.2 (trigger No 915091, 22h 26m 07.44s , -41d 13m 15.60s, R=0.05) errorbox 18 sec after notice time and 44 sec after trigger time at 2019-07-18 04:41:59 UT, with upper limit up to 17.0 mag. Observations started at twilight. The observations began at zenit distance = 40 deg. The sun altitude is -11.6 deg.
MASTER-OAFA robotic telescope located in Argentina (OAFA observatory of San Juan National University) was pointed to the Swift GRB190718.2 errorbox 32 sec after notice time and 57 sec after trigger time at 2019-07-18 04:42:12 UT, with upper limit up to 17.1 mag. The observations began at zenit distance = 33 deg. The sun altitude is -80.1 deg.
MASTER-IAC robotic telescope located in Spain (IAC Teide Observatory) was pointed to the Swift GRB190718.2 errorbox 55 sec after notice time and 80 sec after trigger time at 2019-07-18 04:42:35 UT, with upper limit up to 16.8 mag. The observations began at zenit distance = 71 deg. The sun altitude is -18.8 deg.
The galactic latitude b = -60 deg., longitude l = 98 deg.
Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1077929
We obtain a following upper limits.
```
Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

      49 |         MASTER-SAAO |  P\ |    10 | 15.7 |
      64 |         MASTER-SAAO |  P\ |    40 | 16.5 |  Coadd
      63 |         MASTER-OAFA |   C |    10 | 15.4 |
      88 |         MASTER-OAFA |   C |    60 | 16.4 |  Coadd
      75 |         MASTER-SAAO |  P\ |    10 | 15.7 |
      86 |          MASTER-IAC |  P| |    10 | 16.2 |
     105 |         MASTER-SAAO |  P\ |    20 | 16.1 |
     120 |         MASTER-OAFA |   C |    20 | 15.7 |
     139 |          MASTER-IAC |  P| |    20 | 16.8 |
     147 |         MASTER-SAAO |  P\ |    30 | 16.3 |
     192 |         MASTER-SAAO |  P\ |   120 | 16.9 |  Coadd
     186 |         MASTER-OAFA |   C |    30 | 15.8 | 
     196 |         MASTER-SAAO |  P\ |    40 | 16.3 | 
     268 |         MASTER-SAAO |  P\ |    50 | 16.3 |
     271 |         MASTER-OAFA |   C |    50 | 16.1 |
     339 |         MASTER-SAAO |  P\ |    60 | 16.3 |
     429 |         MASTER-SAAO |  P\ |   240 | 17.0 |  Coadd
     374 |         MASTER-OAFA |   C |    70 | 16.2 |
     430 |         MASTER-SAAO |  P\ |    80 | 16.3 |
     497 |         MASTER-OAFA |   C |    90 | 16.3 |
     536 |         MASTER-SAAO |  P\ |   100 | 16.3 |
     643 |         MASTER-OAFA |   C |   120 | 16.5 |
     808 |         MASTER-OAFA |   C |   450 | 17.1 |  Coadd
     664 |         MASTER-SAAO |  P\ |   120 | 16.2 | 
     815 |         MASTER-SAAO |  P\ |   150 | 15.9 |
     821 |         MASTER-OAFA |   C |   150 | 16.5 |
    1027 |         MASTER-OAFA |   C |   180 | 16.6 |
    1247 |         MASTER-OAFA |   C |   180 | 16.5 |  
    1468 |         MASTER-OAFA |   C |   180 | 16.5 |
    1691 |         MASTER-OAFA |   C |   180 | 16.5 |  
```
Filter C is a clear (unfiltred) band.
The observation and reduction will continue. The message may be cited.
GCN Circular #25084
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team.
Using 1160 s of XRT Photon Counting mode data and 2 UVOT images for GRB 190718A, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 336.57610, -41.20446 which is equivalent to:
```
RA (J2000): 22h 26m 18.26s
Dec (J2000): -41d 12' 16.1"
```
with an uncertainty of 1.7 arcsec (radius, 90% confidence).
This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177).
This circular was automatically generated, and is an official product of the Swift-XRT team.
GCN Circular #25085
Martin Jelinek, Jan Strobl (ASU CAS Ondrejov, CZ), Martin Masek, Petr Janecek, Sergey Karpov, Jakub Jurysek, Jan Ebr, Ronan Cunniffe, Petr Travnicek and Michael Prouza (Institute of Physics, Prague, CZ)
report:
The 30cm robotic telescope FRAM-Auger in Malargue (Argentina) reacted robotically to the Swift/BAT alert of GRB190718A (D'Elia et al., GCNC 25082), starting with a series of 20s unfiltered images at 04:45:11 UT, i.e. 236s post trigger.
We do not detect any new source at or around the reported X-ray errorbox reported by Evans et al. (GCN 25084) at single frames or a combined 20 x 20s image taken between 236s and 1123s after the initial trigger. The combined exposure has a limiting magnitude r'(AB) = 18.0, as calibrated against the APASS Catalogue.
GCN Circular #25089
S. R. Oates (U.Warwick) and V. D'Elia (SSDC) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 190718A 70 s after the BAT trigger (D'Elia et al., GCN Circ. 25082). No optical afterglow consistent with the XRT position (Evans et al., GCN Circ. 25084) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC            70          219          147         >20.9
u_FC               282          532          246         >20.0
white               70         1184          353         >21.0
v                  612         1061           78         >18.3
b                  538         1159           58         >19.1
u                  282         4874          307         >20.0
w1                 661         4847          235         >19.6
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.01 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #25093
B. Sbarufatti (PSU), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), P. D'Avanzo (INAF-OAB), M.G. Bernardini (INAF-OAB), E. Ambrosi (INAF-IASFPA) , D.N. Burrows (PSU), J. D. Gropp (PSU) and V. D'Elia report on behalf of the Swift-XRT team:
We have analysed 6.4 ks of XRT data for GRB 190718A (D'Elia et al. GCN Circ. 25082), from 70 s to 41.2 ks after the BAT trigger. The data comprise 349 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Evans et al. (GCN Circ. 25084).
The late-time light curve (from T0+4.6 ks) can be modelled with a power-law decay with a decay index of alpha=1.03 (+0.18, -0.17).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.64 (+0.15, -0.14). The best-fitting absorption column is 7.0 (+4.2, -3.8) x 10^20 cm^-2, in excess of the Galactic value of 1.2 x 10^20 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.0 x 10^-11 (4.4 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     7.0 (+4.2, -3.8) x 10^20 cm^-2
Galactic foreground: 1.2 x 10^20 cm^-2
Excess significance: 2.5 sigma
Photon index:	     1.64 (+0.15, -0.14)
```
If the light curve continues to decay with a power-law decay index of 1.03, the count rate at T+24 hours will be 0.011 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 4.5 x 10^-13 (5.0 x 10^-13) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00915091.
This circular is an official product of the Swift-XRT team.
GCN Circular #25097
D. M. Palmer (LANL), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), V. D'Elia (SSDC), H. A. Krimm (NSF), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 190718A (trigger #915091) (D'Elia et al., GCN Circ. 25082). The BAT ground-calculated position is RA, Dec = 336.605, -41.184 deg which is
```
   RA(J2000)  =  22h 26m 25.2s
   Dec(J2000) = -41d 11' 02.7"
```
with an uncertainty of 2.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%.
The mask-weighted light curve shows a main multi-peaked structure that starts at ~ T0 and ends at ~T+17 s. In addition, there is a weak pulse at ~T+700 s, which is at the same time as the large flare seen by the XRT. T90 (15-350 keV) is 720.0 +- 35.8 sec (estimated error including systematics).
The time-averaged spectrum from T+0.1 to T+17.1 sec (i.e., the duration of the main emission) is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.38 +- 0.26. The fluence in the 15-150 keV band is 3.6 +- 0.6 x 10^-7 erg/cm2. The spectral analysis for the total burst duration from ~T0 to ~T+720 s does not produce reasonable fits due to the large quiescent period from ~T+17 s to ~T+700 s. The 1-sec peak photon flux measured from T+0.08 sec in the 15-150 keV band is 1.0 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/915091/BA/

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Jochen Greiner, last update: 19-Jul-2019 [Disclaimer]